Performance Analysis Of Integrated Air-ground Networks With Jointly Wireless Information And Energy Transfer

An integrated air-ground network based on unmanned aerial vehicles(UAVs)is expected to play an important role in future mobile communications due to its wide coverage,high flexibility and low cost.Using UAVs as the platforms of aerial base stations(BSs)enables deployment at a relatively low cost in a very short time in the integrated air-ground network and makes it easier to achieve line-of-sight(Lo S)transmission for better quality of service(Qo S).At the same time,jointly wireless information and energy transfer has has attracted much attention due to its high flexibility and the characteristics of green communication.Focusing on one of the research fields,e.g.,wireless powered communications(WPC),combined with the integrated air-ground network,this paper has analyzed the performance of integrated air-ground networks with jointly wireless information and energy transfer.It enables user equipments(UEs)to efficiently perform energy harvesting(EH)and use the collected energy for information transmission,which can effectively solve the problem of insufficient power and blocked information transmission of the UEs in emergency situation,so as to ensure keep in touch with the outside world timely.However,up to now,no literature makes an intensive study of the integrated air-ground network with jointly wireless information and energy transfer.Firstly,this paper studies the performance of the wireless powered communication network(WPCN)over the ground.We put emphasis on the research on WPCN model with randomly deployed power beacons(PBs)and BSs,in which the uplink user is able to simultaneously collect energy from the radio frequency(RF)signals from the BSs and PBs to maintain its transmit power.It suggests a green way for communications.PB can radiate energy isotropically or directionally towards UEs resorting to beamforming,which is called isotropic mode or directed mode respectively.We analyze the energy collected by the UEs for the isotropic mode and directed mode.Considering the maximum allowable transmit power(MATP)of the mobile device,we derive the outage probability and successful probability with the Qo S requirements satidfied.Through numerical simulation,we analyze and compare the outage probability and successful probability in different PB modes,and obtain a better deployment scheme for the network.Based on the research on WPCN over ground,this paper further studies the situation that the terrestrial network cannot cover,and considers the integrated air-ground network with jointly wireless information and energy transfer,which consists of the terrestrial BSs and the aerial BSs.The aerial BSs and the terrestrial BSs are used as the energy sources to supplement the energy for UEs while communicating with the them.Using stochastic geometry theory,this paper models the aerial BSs,terrestrial BSs and UEs in the integrated air-ground network as independent poisson point processes(PPPs).Firstly,we consider the Lo S and non-line-of-sight(NLo S))transmissions of the air-ground links between the aerial BSs and the UEs.We uses the Rician model to fit the channel of the air-ground links.Compared with traditional networks,the interference environment is more complex in the integrated air-ground network.We analyze the interference from the aerial BSs and the terrestrial BSs respectively,and drive the expression of the energy collected by the UEs.On this basis,we focus on the study of outage probability and successful probability of the integrated air-ground network.Finally,through the numerical results,we analyze the influencing factors of UEs’ harvested energy and the impact of terrestrial BSs and the aerial BSs deployments on network performance.The simulation results show that by properly deploying the aerial BSs or terrestrial BSs,the performance of the networks can be effectively improved,which can reduce the cost and guarante the Qo S of the UEs.Although this paper has made some study on the performance of integrated air-ground networks with jointly wireless information and energy transfer,there are still some shortcomings.Further research on some aspects is still needed in the future.Considering the situation of emergency rescue,the data rate demand is relatively low,and the energy collected from the RF signal of BSs can basically meet the UEs’ needs.Therefore,this paper does not consider the randomly deployed PB in the integrated air-ground network.However,for the case where the data rate demand is large,PBs can be introduced into the integrated air-ground network to supply power to the UEs.On the other hand,we only consider the outage probability and the successful probability in this paper.In order to better evaluate the performance of the networks,the energy efficiency(EE)can be further studied in the future.